Too many pop-ups. Found nail.exe

Please help me. I am getting the message AUNPS2.DLL everytime I log on. I also get pop-ups like crazy now. I deleted the file nail.exe before I got more information explaining that that would not fix the problem.

if your anti-virus doesn't detect spy-ware and some other viruses etc, dowload panda active online scan, its free. it will delete some viruses but won't delete spy-ware but it will tell where to find them for deletion.when you delete these files etc, disable system recovery first. panda works for me and i run norton.
its worth using another one to check that the one you already have is doing its job. www.pandasoftware.com/activescan

Thanks for all the help! I was a little intimidated by the HiJackThis instructions, but I was willing to give it a try. However, ewido seems to have done the trick for me. When I have more time I still want to try the HiJackThis method. ewido is only free for 14 days.

this virus, if your AV software (what is it, btw?) doesn't clean it up, i reccomend looking for a removal tool. this can be found at numerous sites, but i'd try the symantec security center first (security.symantec.com)